after coming upon TFP, I found my CYA levels to be over 100 or so due to my inexperienced use of tabs. After (2) 75% drain and refills, I had my CYA down to what I believe to be approx. 60. I had been religiously been keeping my free cl levels at the recommended levels, but somehow noticed some patches of yellow looking stuff on my pool bottom which I assumed was algae. Thought maybe my CYA was still a little high, I did another 75% drain and refill and currently have my cya down to what I believe to be 35-40. I am subsequently going thru a SLAM, trying to keep my free cl level at approx. 20 slam level. I am losing approx. 3-4 ppm free cl overnite, but consistently test no combined chlorine. We haven't had a lot of sun over the last several days, so I'm wondering what is eating my cl? More questions.... Is it possible to have something organic eating my chlorine but show no combined chlorine? If I show no CC, does that mean I have no organics? I realize my CYA is a little low and am trying to raise it via judicious use of tabs, is this realistic? Also, I read on here somewhere, that one tab raises cya by 9ppm. Can someone explain how that correlates with the readings on my taylor fas-dpd kit? And lastly, Is there any other way to test cya other than this black dot deal, as it seems very subjective, unlike a color change test.
Thanx,
Dave.
Thanx,
Dave.